1. Field of the Invention
Apparatus for introducing a fluid into a container An apparatus for introducing a fluid into a container is used in particular for subsequent stabilization of substances which are usually stored in containers or storage tanks and which are distinguished by a strong tendency toward undesirable chemical reactions, for example premature polymerization, or other physical reactions, for example crystallization.
2. Discussion of the Background
It is known that certain substances or combinations of substances in solid or dissolved form are suitable for restabilizing the polymerizable substances which react at an undesirable time. These substances can be introduced into the stored material in a conventional manner and then mixed with the tank content by means of the pump which is usually used for tank farm facilities and which is provided for the purpose of filling and emptying tanks. The disadvantage here is that pumps themselves may be the starting point of a premature polymerization which causes blockage of the pump. Consequently, the mixing function can no longer be performed when required. A further disadvantage is the dependence on an external energy source for driving the pump, which, as a result of an emergency or by chance, may not be available, so that stabilization liquid cannot be introduced.
In order to be independent of external energy sources, a mixing process involving blowing in gases is therefore also used. A disadvantage of this is that additional baffles in or on the tank itself would have to be provided for this purpose. As a rule, such baffles must be firmly anchored to the tank in order to prevent them from being damaged or torn off during normal operation. In order to be effective, ie. to achieve good mixing, baffles for forcing in gases are usually located close to the bottom of the tank. When these baffles are not in use, the reactive substance can penetrate into the baffles and will gradually polymerize there owing to the slight exchange of material, so that, when required, the gas supply will be useless. A small air stream is therefore often passed through such lines in order to keep these lines free. However, such an air stream likewise needs to be monitored by means of apparatuses to prevent the liquid stored in the tank from rising and to keep the line open. Such designs have proven expensive for reliably performing the intended function.
EP-B 0 064 628 describes an apparatus for the emergency stoppage of polymerization reactions in a closed reaction container by the addition of inhibitor solution. The addition is effected in the lower region of the container via a connecting flange closed with a bursting disk. Mounted on this connecting flange is an angled riser line to an upper flange to which a pressurized gas line is connected. The riser line is filled with inhibitor solution which, when required, is forced into the container by the pressurized gas.
Although the operability of the apparatus should be independent of caked polymers and failure of the energy supplies, the regular monitoring usually required for safety apparatuses is more difficult in the case of these immersed baffles, and the bursting disk can be checked only when the container is empty. However, this means that the tank cannot be used during cleaning and checking.